Calculations of the thermal and fast neutron fluxes in the Syrian miniature neutron source reactor using the MCNP-4C code

The MCNP-4C code, based on the probabilistic approach, was used to model the 3D configuration of the core of the Syrian miniature neutron source reactor (MNSR). The continuous energy neutron cross sections from the ENDF/B-VI library were used to calculate the thermal and fast neutron fluxes in the inner and outer irradiation sites of MNSR. The thermal fluxes in the MNSR inner irradiation sites were also measured experimentally by the multiple foil activation method (¹⁹⁷Au (n, γ) ¹⁹⁸Au and ⁵⁹Co (n, γ) ⁶⁰Co). The foils were irradiated simultaneously in each of the five MNSR inner irradiation sites to measure the thermal neutron flux and the epithermal index in each site. The calculated and measured results agree well.     

Evaluation of the suitability of various gamma lines for the gamma spectrometric determination of 238U in environmental samples.

Gamma-ray spectrometry is extensively used for 238U determination because of its simplicity in terms of sample preparation. Nevertheless, processing of measurement data presents several challenges, such as evaluation of overlapping photopeaks and calibration of detector efficiencies for different matrices and photon emissions. Besides, the emission probability data for 238U and its daughters show significant discrepancies among different studies. In this study, we assess the suitability of four methods, using the photopeaks at 63.3, 92.6, 766.4 and 1001.0 keV, respectively, to determine 238U in environmental samples. With that aim we analyse several reference and environmental samples, detailing the entire procedure involved in the calculation of the 238U activities and highlighting possible error sources. Based on the results obtained, we propose new yields for the 234Th photons and compare these to corresponding values from the literature.     

EC comparison on the determination of 226Ra, 228Ra, 234U and 238U in water among European monitoring laboratories

In anticipation of new European requirements for monitoring radioactivity concentration in drinking water, IRMM organized an interlaboratory comparison on the determination of low levels of activity concentrations (about 10–100 mBq L^?1) of the naturally occurring radionuclides ²²⁶Ra, ²²⁸Ra, ²³⁴U and ²³⁸U in three commercially available mineral waters. Using two or three different methods with traceability to the International System of Reference (SIR), the reference values of the water samples were determined prior to the proficiency test within combined standard uncertainties of the order of 3%–10%. An overview of radiochemical separation and measurement methods used by the 45 participating laboratories are given. The results of the participants are evaluated versus the reference values. Several of the participants’ results deviate by more than a factor of two from the reference values, in particular for the radium isotopes. Such erroneous analysis results may lead to a crucial omission of remedial actions on drinking water supplies or to economic loss by an unjustified action.     

Results of fast neutron therapy of adenoidcystic carcinomas of the head and neck at the neutron facility Hamburg-Eppendorf

Between July 1977 and March 1988, 31 patients with an adenoidcystic carcinoma were treated with fast neutrons of a 14 MeV-DT-generator at our department. Primary locations were: parotid gland eight cases, paranasal sinus five cases, submandibular gland five cases, trachea four cases and other locations nine cases. The median follow-up of our patients was 16 months. Most of the patients had advanced tumors. The calculated local control rate is 65% at two years.     

Results of fast neutron therapy of adenoid-cystic carcinomas of the head and neck at the neutron therapy facility Hamburg-Eppendorf

Between 1977 and 1987, 30 patients with adenoid-cystic carcinomas of the head and neck region were treated, at the Hamburg-Eppendorf neutron therapy facility, with a 14 MeV-DT-generator. The present review deals with 15 patients treated before October 1986 e.g. with follow up longer than one year. These results, although preliminary, tend to confirm that fast neutrons is the best irradiation modality of adenoid-cystic carcinomas of the head and neck region, especially when surgery is not possible, or cannot be radical.     

The transfer of uranium isotopes 234U and 238U to the waters interacting with carbonates from Mendip Hills area (England).

Laboratory time-scale experiments were conducted on limestone and dolomite gravels from the Mendip Hills area, England, with the purpose of evaluating the release of 238U and 234U to different aqueous solutions. The 234U/238U activity ratio (AR) lab data were reliable to interpret the field data. The obtained values do not indicate a reduction in the amount of dissolved U and an increase in the AR of the remaining dissolved U as commonly observed for groundwater systems close to redox boundaries.     

A comparison of fast MRI of hips with and without parallel imaging using SENSE

This study was undertaken to qualitatively and quantitatively compare fast MRI of hips with and without parallel imaging using SENSE (sensitivity encoding). 27 patients underwent MRI of the hips with coronal T1 turbo spin echo (TSE) (repetition time (TR) 500 ms, effective echo time (TEeff) 15 ms, Turbo Factor 4), coronal IR-TSE (TR 2000 ms, TEeff 30 ms, inversion time (TI) 160 ms, Turbo Factor 20) and axial T2 TSE (TR 3000 ms, TEeff 80 ms, Turbo Factor 20) weighted images acquired with and without SENSE with a reduction factor of 2. Conventional imaging was performed in 8 min and 36 s. Images acquired with SENSE were acquired in 5 min and 31 s without a discernible reduction in image quality or a significant quantitative reduction in image signal to noise ratio, contrast to noise ratio or edge enhancement.     

通量平滑度在胸中上段食管癌容积弧形调强中的剂量学比较

目的对比Monaco计划系统中3种通量平滑度参数在胸中上段食管癌容积弧形调强(VMAT)中的剂量学差异。方法选取15例胸中上段食管癌病例,相同优化条件下分别使用高、中和低3种通量平滑度(高组、中组、低组)进行VMAT计划设计和评估。比较3组计划靶区的D95、Dmean、适形度指数(CI)、均匀性指数(HI)、危及器官的受量和机器跳数。结果3组计划相比靶区的D95、Dmean、CI和HI等参数差异均无统计学意义(P>0.05)。高组与中和低组相比,心脏的V40、Dmean、双肺的V10、V20、Dmean和子野数差异无统计学意义(P>0.05);与中组和低组相比,高组心脏的V30和脊髓危及器官的计划体积(PRV)Dmax均降低(t=-2.167、-0.999,P<0.05);高组双肺的V5高于中和低组(t=1.306、-2.027、P<0.05);与中组和低组相比,高组的机器跳数降低(t=-3.148、-6.692、P<0.05)。与中组相比,低组的心脏V30和Dmean,脊髓PRV Dmax均增加(t=0.411、0.589、0.013,P<0.05),而肺的V5降低(t=0.423,P<0.05)。结论3组计划均能满足临床要求。综合考虑计划质量和执行效率,建议采用高通量平滑度用于中上段食管癌容积弧形调强放疗。     

Emission probabilities of γ-rays from 238Np and their use for determination of the thermal neutron capture cross section of 237Np

The relevant absolute γ-ray emission probabilities from the β-decay of ²³⁸Np were measured by means of α- and γ-spectroscopic techniques. We obtained values of (25.6±0.4)%, (8.9±0.2)% and (18.8±0.3)% for the 984.45-, 1025.87- and 1028.54-keV γ-rays, respectively, in agreement with the previous measured ones. These intensities were used to deduce the thermal neutron capture cross section of ²³⁷Np for which a value of (182.2±4.5) b is obtained higher by 11% than the recommended value.     

Comparison of high-dose-rate 192Ir source strength measurements using equipment with traceability to different standards

PurposeAccording to the American Association of Physicists in Medicine Task Group No. 43 (TG-43) formalism used for dose calculation in brachytherapy treatment planning systems, the absolute level of absorbed dose is determined through coupling with the measurable quantity air-kerma strength or the numerically equal reference air-kerma rate (RAKR). Traceability to established standards is important for accurate dosimetry in laying the ground for reliable comparisons of results and safety in adoption of new treatment protocols. The purpose of this work was to compare the source strength for a high-dose rate (HDR) ¹⁹²Ir source as measured using equipment traceable to different standard laboratories in Europe and the United States.Methods and MaterialsSource strength was determined for one HDR ¹⁹²Ir source using four independent systems, all with traceability to different primary or interim standards in the United States and Europe.ResultsThe measured HDR ¹⁹²Ir source strengths varied by 0.8% and differed on average from the vendor value by 0.3%. Measurements with the well chambers were 0.5% ± 0.1% higher than the vendor-provided source strength. Measurements with the Farmer chamber were 0.7% lower than the average well chamber results and 0.2% lower than the vendor-provided source strength. All of these results were less than the reported source calibration uncertainties (k = 2) of each measurement system.ConclusionsIn view of the uncertainties in ion chamber calibration factors, the maximum difference in source strength found in this study is small and confirms the consistency between calibration standards in use for HDR ¹⁹²Ir brachytherapy.     

Effect of training on weight and certain physiological parameters of Indian female hockey players with respect to their field positions

The present study was conducted on 18 female players of the Punjabi University hockey team during their camp held at Punjabi University from 4.10.1988 to 24.10.1988; before participating in the Inter-varsity competition held at Ranchi. Weight, heart rate and blood pressure of each subject was taken before doing the exercise on the treadmill. The players were asked to run on the treadmill for four minutes at the speed of 10 km/hr. Recovery heart rate and blood pressure were also taken. All these tests were taken twice on each player, i.e. initially at the commencement of the training and finally at the completion of the training camp. It has been observed that there is a reduction of body weight in all the categories of players, the maximum being in halves (2.5 kg). There is an improvement in the percentage recovery in the heart rates of all the categories of players except the halves where the recovery is much less at the end of the training camp as compared to the values in the beginning of the camp.     

Separation and quantification of 238U, 232Th and rare earths in monazite samples by ion chromatography coupled with on-line flow scintillation detector.

An alternative procedure has been described for efficient separation and quantitative determination of uranium (U), thorium (Th) and rare earth elements (REEs) in monazite mineral by high performance ion chromatographic system (IC). Different variables affecting the distribution coefficient, the retention and hence separation efficiency such as eluent flow rate and concentrations of HCI and ammonium sulfate (NH4)2SO4 containing the mobile phase were studied. The developed separation protocol of U, Th and REEs was optimized using an Ion Pac CS5 separation column followed by post-column derivatization reaction with Arsenaso III and UV-VIS spectrophotometric detection. Comparative evaluation of U, Th and REEs concentration in monazite mineral was demonstrated using two different on-line detection modes including flow through cell scintillation detector (FSD) and UV-VIS spectrophotometer. Response of the FSD was found to be linear over the full range of activities investigated (4-100 Bq). The lower limits of detection (LLD) for the investigated radionuclides were 3.0+0.1 Bq for 238U and 6.0 +/- 0.1 Bq for 232Th. The detection of 238U and 232Th by FSD shows good agreement with the corresponding determination by UV-VIS spectrophotometer. The content of ThO2 and U3O8 in monazite sample were found to be 4.7 +/- 0.1% and 0.42 +/- 0.04% using UV-VIS detector and 4.3 +/- 0.1% and 0.45 +/- 0.1% using FSD, respectively.     

Accuracy and precision of 238Pu determination at fg level by alpha spectrometry using 239Pu and 240Pu amount analyzed by ICP-MS

The accuracy and precision of the determination of ²³⁸Pu amount at the fg (mBq) level by a combination of alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS) were studied using a standard reference material (CRM 136—Plutonium Isotopic Standard, National Bureau of Standards, Washington, D.C., USA). The activity of ²³⁸Pu was calculated from the amount of ²³⁹Pu and ²⁴⁰Pu obtained by isotope dilution method and ICP-MS combined with the intensity ratio of ²³⁸Pu/^239,240Pu obtained by alpha spectrometry without adding spike. The results show that approximately 130 fg of ²³⁸Pu can be analyzed within an accuracy of 7% bias and with 5–12% of total uncertainty. The examined analytical procedure was applied to the quantitative analysis of ²³⁸Pu in water samples representing Safeguards inspection samples. The combination of alpha spectrometry and ICP-MS is useful for quantitative and isotopic analysis in low-level Pu samples. Also the method leads to improving the accuracy of ²³⁸Pu determination because efficiency calibration is not necessary for alpha spectrometry.     

全海深载人潜水器不同驾驶位人员的下肢循环和肌肉疲劳分析

目的:分析全海深载人潜水器舱室不同驾驶位人员长时间保持不规则体位后的下肢血流量和表面肌电图变化,为舱室设计提供参考。方法:研究分为主驾驶坐位、副驾驶坐位和副驾驶观察位三部分。不同驾驶位的方案1为有挡板支撑,方案2为无挡板支撑。单次主驾驶坐位试验时长为2 h,单次副驾驶坐位和副驾驶观察位试验时长均为1 h。分别在主驾驶位、副驾驶位及观察位测定受试对象的下肢血流量、斜方肌、竖脊肌及股直肌的表面肌电图。结果:与主驾驶静息对照值相比,主驾驶坐位两个方案的下肢血流量均有所增加,且方案2的下肢血流量较方案1有减小趋势;与副驾驶静息对照值相比,副驾驶坐位两个方案和副驾驶观察位两个方案的下肢血流量均显著增加,差异有统计学意义( P<0.01);主驾驶坐位方案2中竖脊肌在2 h时的平均频率较方案1显著增加,差异有统计学意义( P<0.05);与副驾驶静息对照值相比,副驾驶坐位两个方案和副驾驶观察位两个方案的斜方肌、竖脊肌和股直肌表面肌电平均频率和平均功率显著增加,差异有统计学意义( P<0.05或 P<0.01);与副驾驶坐位和观察位方案1相比,副驾驶坐位和观察位方案2的股直肌平均频率和平均功率有不同程度的升高趋势。 结论:全海深载人潜水器舱室内如配置可伸缩的活动挡板,可以兼顾副驾驶坐位和观察位的生理特征,减低肢体疲劳,提高作业绩效。     

Semi-automatic measurement of left ventricular function on dual source computed tomography using five different software tools in comparison with magnetic resonance imaging

PurposeTo compare left ventricular (LV) function assessment using five different software tools on the same dual source computed tomography (DSCT) datasets with the results of MRI.Materials and methodsTwenty-six patients, undergoing cardiac contrast-enhanced DSCT were included (20 men, mean age 59 ± 12 years). Reconstructions were made at every 10% of the RR-interval. Function analysis was performed with five different, commercially available workstations. In all software tools, semi-automatic LV function measurements were performed, with manual corrections if necessary. Within 0–22 days, all 26 patients were scanned on a 1.5T MRI-system. Bland–Altman analysis was performed to calculate limits of agreement between DSCT and MRI. Pearson's correlation coefficient was calculated to assess the correlation between the different DSCT software tools and MRI. Repeated measurements were performed to determine intraobserver and interobserver variability.ResultsFor all five DSCT workstations, mean LV functional parameters correlated well with measurements on MRI. Bland–Altman analysis of the comparison of DSCT and MRI showed acceptable limits of agreement. Best correlation and limits of agreement were obtained by DSCT software tools with software algorithms comparable to MRI software.ConclusionThe five different DSCT software tools we examined have interchangeable results of LV functional parameters compared to regularly analysed results by MRI.The best correlation and the narrowest limits of agreement were found when the same software algorithm was used for both DSCT and MRI examinations, therefore our advice for clinical practice is to always evaluate images with the same type of post-processing tools in follow-up.     

A prospective study of health problems at the 2018 17/U and 19/U Australian National Netball Championships with comparison of surveillance methodology

ObjectiveTo investigate the incidence, site, nature and cause of injuries sustained during and four weeks following the 2018 Australian National Netball Championships (ANNC’s) using medical attention and self-report surveillance tools.DesignProspective cohort study.MethodInjuries were recorded prospectively using medical attention and self-report data collection methods. One hundred and ninety-two athletes competed at the 2018 ANNC’s with 96 athletes in each age group (17/U & 19/U).ResultsThere were 103 medical attention injuries sustained by 80 athletes resulting in an incidence rate of 89.4 per 1000 player hours. The most frequently recorded medical attention injury diagnoses across both age groups were lateral ankle ligament sprain (n = 14, 13.6%), foot blisters (n = 11, 10.7%), and lumbar pain (n = 10, 9.7%). Ankle sprains (n = 4), anterior cruciate ligament (ACL) ruptures (n = 3) and concussion (n = 3) recorded as the highest sports incapacity injuries. The self-report data collection revealed that 46 (27.2%) athletes arrived at the tournament with an existing self-reported injury/illness and 57 (39.3%) athletes had a self-reported injury/illness at the conclusion of the ANNC (RR 1.44 95%CI 1.05–1.99, p = 0.030).ConclusionThere are no recent studies reporting injury rates specifically in pre-elite netball players. This study found an incidence rate of 89.4 per 1000 player hours. Ankle sprains are the highest medical attention and sports-incapacity injury in pre-elite netball athletes. Foot blisters and low back pain also feature in the highest medical attention injuries and ACL rupture and concussion were high sports incapacity injuries at the ANNC’s. Finally, combining both the medical attention and self-report injury/illness data collection methods identified more injuries/illnesses than the use of one method alone.     

High- and low-osmolar contrast agents in urography: a comparison of the appearances with respect to pyelotubular opacification and renal length

The incidence of pyelotubular opacification and the change in renal length during intravenous urography with iohexol (Omnipaque) was compared with sodium/meglumine diatrizoate (Urografin). Pyelotubular opacification was seen in 14 out of 29 urograms performed with iohexol compared with one out of 28 urograms performed with sodium/meglumine diatrizoate. This increased incidence is statistically significant and has not been previously documented. The increase in renal length following intravenous contrast medium was similar for both iohexol and sodium/meglumine diatrizoate. The significance of these findings with respect to the interpretation of urograms performed with iohexol is discussed.     

Dual‐source parallel RF transmission for diffusion‐weighted imaging of the abdomen using different b values: Image quality and apparent diffusion coefficient comparison with conventional single‐source transmission

Purpose:

To prospectively and intraindividually evaluate what effects dual‐source parallel radiofrequency (RF) transmission have on image quality and apparent diffusion coefficient (ADC) of abdomen diffusion‐weighted imaging (DWI) using different b values, compared with the single‐source RF transmission.

Materials and Methods:

Eighteen healthy male volunteers were enrolled in this Health Insurance Portability and Accountability Act (HIPAA)‐compliant Institutional Review Board (IRB)‐approved study. Abdominal DWI was performed with dual‐source and single‐source RF transmission at 3.0 T using a series of b‐value combinations: 0/100, 0/500, 0/800, and 0/100/800. RF field homogeneity, subjective image quality, and signal to noise ratio (SNR) of each abdominal organ were evaluated. ADC values were calculated for each abdominal organ. Wilcoxon test and repeated‐measures analysis of variance was used to calculate statistical significance.

Results:

The parallel RF transmission significantly improved homogeneity of the RF field (P = 0.0001–0.008) and subjective image quality (P < 0.0001) at each b value and also increased SNR. At lower and higher b value, the measured ADC of lateral left hepatic lobe and spleen between dual‐source and single‐source images were significantly different (P = 0.0001–0.047). At b = 0/500, there was no significant difference in ADC measurements between dual‐source and single‐source RF transmission for abdominal organs, except a slight statistically significant difference for spleen (P = 0.047).

Conclusion:

Parallel RF transmission significantly improved the image quality and homogeneity of the RF field. The RF transmission had a significant influence on measured ADC of lateral left hepatic lobe and spleen. At b = 0/500 the influence was minimum for all abdominal organs. J. Magn. Reson. Imaging 2013;37:875–885. © 2012 Wiley Periodicals, Inc.